Show degrees for AN/DN

[jd284]

Currently the AN/DN nodes show the ascending/descending velocity in m/s.

However when experimenting with different flight plans for an off-plane rendezvous or other plane change, it would be more helpful to know the ascending/descending angle instead, because the node velocity depends strongly on the altitude of the node (from of the resulting ship speed), and so comparing the AN/DN between two flight plans is difficult: to see which one provides a better plane alignment, first the plans have to be adjusted so that both have their nodes at the same altitude, and comparing plans with intentionally higher/lower AN/DN becomes infeasible.

Of course when actually creating a maneuver at the node, the velocity is also important to know, so ideally I would like to see both velocity and angle, or some way to toggle between both, possibly even auto-toggling every second.